Thermodynamically-efficient local computation and the inefficiency of quantum memory compression
- Author(s): Loomis, Samuel P
- Crutchfield, James P
- et al.
Published Web Locationhttps://doi.org/10.1103/physrevresearch.2.023039
Modularity dissipation identifies how locally-implemented computation entails costs beyond those required by Landauer's bound on thermodynamic computing. We establish a general theorem for efficient local computation, giving the necessary and sufficient conditions for a local operation to have zero modularity cost. Applied to thermodynamically-generating stochastic processes it confirms a conjecture that classical generators are efficient if and only if they satisfy retrodiction, which places minimal memory requirements on the generator. This extends immediately to quantum computation: Any quantum simulator that employs quantum memory compression cannot be thermodynamically efficient.